Currents (GlobCurrent)
ProHow fast the surface current runs, worked out from satellite sea height plus the push of the wind. A daily average with no tide in it, and less reliable close to the coast.
Updates daily
More detail
With the standard colors, dark purple and blue are slow water, green and yellow are faster, and orange to dark red is the fastest. The color scale runs from still water to about 3.4 knots. On the website the crosshair readout gives the speed in knots when your distance unit is nautical miles. The Currents button on the bottom bar shows direction, but on the Observed tab its moving arrows or streaks follow the Currents (DUACS) measured current, not this one.
How to use it. Use it for the big flow, such as the Loop Current and the big eddies.
How it relates to the other current layers. Currents (DUACS) starts from the same satellite sea height measurements on a finer grid, but it carries no wind push. Currents and Currents at Depth, on the Forecast tab, are the HYCOM (U.S. Navy model) forecast, with wind and tide and finer detail. Use Currents (DUACS) for the big flow from the slope of the sea surface alone, Currents (GlobCurrent) to see the same flow with the wind's push added, and the forecast Currents layer for the shelf break, the tide and anything close to shore. All of them share one color scale.
Who makes it. The Copernicus Marine Service, the European Union's ocean data service, makes it under the name GlobCurrent, from satellite measurements and measurements taken in the water.
Where it covers. Copernicus makes it for the whole world's oceans, and the app shows it in every region the app covers.
Know its limits before you use it.
- The newest picture is about a day old.
- Its makers say it reads too slow in the Gulf Stream.
- An hour's drift at the surface will not match it.
- Its cells are about 15 nautical miles across, so it shows the big flow, not a rip.
If the map is blank on today's date, step back one day.
The numbers
| How often it updates | Once a day, one frame per day |
| How fresh it usually is | About 1 day behind |
| How detailed it is | About 15 nautical miles per cell |
| Where it covers | Everywhere the app shows ocean data |
| How far back you can look | 8 days back |
| Observed or modeled | Worked out from satellite sea height and wind data, averaged over a whole day |
| What you see on screen | Speed only. Surface only |
Source: a satellite picture from GlobCurrent, from satellite sea height and wind (Copernicus).